Slide-rule



J. HEMMI SLIDE RULE.

APPLICATION FILED MAR. 3p, 1917.

,329,902. Patented Feb. 3, 1920.

JIRO HEMMI, OF TOKYO, JAPAN.

SLIDE-RULE.

Specification of Letters Patent. 7

PatentedFeb. 3, 1920.

Application filed March 30, 1917. Serial No. 158,555.

To all whom it may concern:

Be it known that I, J IRO HEMMI, a subject of the Emperor of Japan,residing at Tokyo, Japan, have invented-certain new and usefulImprovements in Slide-Rules, whereof the following is a specification.

The object of this invention is to provide a slide rule having a hardantifriction and non-absorbent surface which will avoid the expansionsand contractions due to changes from dry to moist or moist to dryatmospheres and facilitate the movement of the slide.

In the accompanying drawings Figure 1 is a perspective view of a sliderule embodying this invention.

Fig. 2 is an end View of the stock or body.

Fig. 3 is an end view of the slide or strip.

Fig. 4 is a plan of a modified slide rule and Fig. thereof.

In the form of embodiment shown in Figs. 1 to 3, this slide rulecomprises a laminated 5 is a transverse sectional view stock 1 composedof parallel bars 2, 2 disposed apart from each other, an intermedlateplate 3 connecting said bars and a laminated slide 4 movable betweensaid bars.

One bar of the stock 1 is composed of a base layer a; and a top layer 6,the latter being provided with a groove or slideway c on its inner faceand the other bar is composed of a base layer 03 and a top layer 6, thelatter being provided with a slideway or oove f on its inner face.

The slide 4 is composed of a base layer 9, a top layer h and side layers91 and 9' disposed vertically of said base and top layers and coveringthe edges thereof. The said layer 71 is provided on its outer face witha tongue 70 adapted to fit the slideway 0 and the side layer j isprovided with a tongue Z adapted to fit the slideway f. The base and toplayers 9 and h are composed of bamboo strips disposed back to back andcemented together and the side layers 11 and j are composed of bamboostrips cemented to the sides of said base and top strips and coveringthe joint between them.

The fibers of bamboo are always longitudinal and of a hard and siliciouscharacter which is non-absorbent of moisture and provides smooth,unchanging antifriction surfaces between the slide and its stock.

The parallel bars 2, with scale plates m, suitable material containingthe graduations and the slide may be provided with a scale plate 0composed of celluloid or other suitable material for its graduations.

The parallel bars of the stock are connected by the sheet metal strip 3so that, if excessive clearance is produced between the contact surfacesof the stock and the slide by wear, the sheet metal strip may beslightly bent in such a manner that the two ed es can approach eachother.

11 another embodiment of this invention, illustrated in Figs. 4: and 5,the parallel bars 2, 2 of the stock are separable one from the other, aconnecting plate 6 being fastened to 2 may be provided a of celluloid orother one of said bars and detachably connected to the other byinserting the free edge thereof in a slot in said other member. Theplate 6 may be fastened to said other memberby a set screw 7 or othersuitable means. By this construction the two parallel bars may beadjusted to increase or .ance between them.

It must be understood that the present inventlon is not limited to theconstructions above described, but the construction may decrease theclear- 7 bamboo fibers forming non-absorbent anti- 1iriction slidingsurfaces between said memers. I

In testimony whereof I have signed my name to this specification in thepresence oftwo subscribing witnesses.

J IRO HEMMI.

Witnesses:

R. KUSAKA, H. F. HAWLEY.

